Modern wind turbines comprise a plurality of wind turbine rotor blades, typically three blades, each blade today having a weight of up to 15 tons and a length of up to 55 meters.
Traditionally, a blade comprises two shell parts, one defining a windward side shell part and the other one defining a leeward side shell part. To reinforce such a blade a box-shaped, longitudinal and tubular element, i.e. a spar, can act as a reinforcing beam. The spar is located in the cavity between the two wind turbine shell parts and extends substantially throughout the shell cavity in order to increase the strength and stiffness of the wind turbine blade.
As the size of wind turbines and thus wind turbine blades are still growing, the production facilities and the transport means must be upgraded to handle blades of the required size. This also increases the demand on logistics and increases the associated costs.